Federal agencies will be forced to shut down or drastically scale back services if Congress and President Barack Obama do not come to an agreement to fund the government by 11:59 p.m. on Monday, Sept. 30.

Even though a shutdown is considered unlikely by most federal lawmakers, the White House is warning agencies to plan ahead.

The shutdown is related to the partisan debate circling the Affordable Care Act, also known as Obamacare, and whether the debt ceiling should be raised. Without an agreement from Congress, the U.S. Treasury will be forced to prioritize remaining funding distributed to agencies.

A shutdown doesn't mean the federal government will grind to a complete halt. Services deemed essential to health and national security, such as the military, air traffic controllers and meat inspectors, will still be working. Some federal employees will be called to work, although paychecks will not be waiting for them at the end of the week.

With more than 157,000 government employees in the region, Hampton Roads would be hit particularly hard by a shutdown. More than 71,000 people are employed by the military in the metropolitan statistical area, according to the U.S. Census Bureau.

Here is how the federal shutdown may affect you:

Military

Members of the military, including those in conflict zones, may have their paychecks delayed during a shutdown, according to a news article from the Stars & Stripes, quoting Pentagon press secretary George Little on Monday.

The Oct. 1 payday is not in jeopardy because that money will already have been transferred to bank accounts. The mid-October payday would be delayed if the Defense Department does not have short-term funding available.

Civilian workers would require an act of Congress to receive retroactive pay.

Federal law enforcement agencies deemed necessary for the nation's safety would continue working, including the FBI, Border Patrol and Coast Guard.

Newport News Shipbuilding

The effect of a government shutdown on Newport News Shipbuilding is expected to be "minimal" said Christie Miller, a company spokeswoman.

More than 20 percent of federal contractors were negatively impacted by the last government shutdown, in 1995-96, according to a Congressional Research Service report published in August.

Federal courts

The Administrative Office of U.S. Courts, which provides services to the federal judicial system, says it is determining how long courts could stay open during a shutdown.

"We don't know how long we can keep the courts open, but it won't be for that long," said Karen Redmond, a spokesperson with the Administrative Office, in Washington, D.C.

If a shutdown occurs, the courts could stay open "more than three or four days but less than a month" using fees collected to pay expenses.

Federal prosecutors

A call to the U.S. Attorney's Office in Washington was forwarded to the Office of Management and Budget, an arm of the White House, which released a statement saying specific programs are being reviewed as agencies plan for a potential shutdown.

Jefferson Lab

A spokeswoman said it was unclear whether funding from the Department of Energy would be affected by a shutdown, although workers should know by the end of this week.

National parks

Colonial National Historical Park officials referred questions to a spokesman for the Department of the Interior.

Jessica Kershaw, Department of Interior spokeswoman, said the agency is reviewing its plans if funding is no longer available.

When previous federal shutdowns were looming, local park officials made preparations to close the Colonial Parkway because there would be no rangers to patrol it.

Mail service

Mail will be delivered, but Postal Service employees may not be paid until the government is restarted.

Airports

Transportation Security Administration officers would continue to staff checkpoints including at Newport News Williamsburg International Airport, although they may not be paid until the government is restarted.

Applications would be left untouched until federal workers returned to their jobs.

Federal employees

Workers will be treated differently depending on their job classification. Positions deemed necessary to national security will remain staffed. Positions not necessary will be furloughed until money becomes available.

Workers still on the job may not receive pay checks until Congress passes a spending plan.

Federal benefits

Funding for entitlement benefits is considered mandatory and not part of the annual appropriation process. The money will be available, but whether the workers who process them will be forced to stay home is still a question.

Social Security checks were distributed during the last federal shutdown.

Doctors and hospitals will continue to receive Medicare and Medicaid reimbursements.